Still not sure about amd vs intel, but you might want to opt for an AMD Dual core if your're on a medium budget, and here's why. A dual cpu mobo requires a set of ram for each cpu but a dual core does not. An extra 2 gigs of DDR will cost you about as much as the dual-core technology anyways. I also say AMD because they tend to be less expensive than their intel equivalents. They are also rated to outperform at certain task--i'm not sure if 3D modelling is one of them but that's where the video card comes in. I got a Radeon 9250 256M DDR AGP card for like 50 bucks off ebay. I read here http://hardware.slashdot.org/article.pl?sid=05/05/04/1410221&from=rss
that ATI's 512MB video card doesn't really outperform their higher end 256MB cards.